This invention relates generally to the field of bending dies, also known as shoes or rams, which are used in connection with various types of bending equipment to cold bend pipes or tubes, where the bending die has a curved bending channel to receive the tube, and the tube and die together are advanced against or between fixed members or rollers to impart a bend in the tube.
Tube bending equipment for forming a curved metal tube are well known in the art. One type of such equipment consists of a bending die which has a semi-circular tube-receiving channel, where the bending die is mounted onto an actuator means or ram capable of advancing the die with sufficient force to create a bend in the tube. The tube is mounted in the bending channel and the die is advanced between a pair of lateral rollers, fixed in position, each of the rollers also having a channel to receive the tube. As the die advances between the lateral rollers, the tube is bent. A representative example of this type of bending equipment is shown in U.S. Pat. No. 2,880,779 to Mingori. The general state of the art was improved by my U.S. Pat. No. 5,237,847, in which an extended forward lip was provided on the bending shoe to prevent folding and creasing of thin-walled tubes during the bending process, and the disclosure of that patent regarding the operation of bending equipment utilizing such a bending die is incorporated herein.
A different problem encountered in the field is addressed in this instance, namely the problem associated with creating a bend in a tube having an attached fitting on its end such that the tube is bent immediately adjacent the fitting. Prior designs for bending shoes incorporate a pair of parallel lateral channels extending to the rear of the bending channel. This enables the bending shoe to advance forward enough relative to the lateral rollers to impart a full 180 degree bend in the tube. Because of the presence of these lateral channels in the bending die, a bend could not be made at the extreme close end of a tube having a fitting, such as a flared nut or the like, since with the fitting abutted against the back side of the bending die the immediately adjacent portion of the tube was received in the straight lateral channel and would remain unbent to until the point where the semi-circular bending channel began.
It is an object of this invention to provide a bending die for use in tube bending equipment where the die is structured such that a bend can be imparted into a tube having a fitting at a point immediately adjacent the fitting. This and other objects which will be apparent from the disclosure to follow are accomplished by providing a fitting recess or notch in one side of the bending die which allows the fitting to be positioned abutting the semi-circular bending channel during the bending operation.